1. Field of the Invention
The present invention relates to an image processing device and method, and a storage medium in which color images are gray-scale converted.
2. Related Background Art
In an ordinary printing apparatus, to emit a monochromatic output of color designation such as RGB system, after density is converted from RGB system to a gray scale, a dither method or another binarizing method is generally used to output a pseudo gradation. Generally, the following equation is used as a conversion equation from RGB system to gray-scale density:
Gray=1000xe2x88x92(290xc3x97R+605xc3x97G+105xc3x97B)/1000
In the aforementioned prior art, however, in the RGB system, there is a case where even different colors have the same density by density conversion.
In a printing apparatus in which each RGB color data of 0 to 1000 can be represented up to monochromatic 1000 gradations by the pseudo gradation, when the density conversion is performed in accordance with the above conversion equation, for example, density (R, G, B)=(500, 0, 100) results in:
xe2x80x83Gray=1000xe2x88x92(290xc3x97500+605xc3x970+105xc3x97100)/1000=845
Moreover, density (R, G, B)=(400, 48, 100) results in:
Gray=1000xe2x88x92(290xc3x97400+605xc3x9748+105xc3x97100)/1000=845
These two colors are converted to the same density.
Therefore, in such case, two colors are outputted at the same density during the monochromatic output, and color difference cannot be distinguished. Especially, when drawing is performed in such a manner that two colors are partially overlapped or allowed to abut on each other, the boundary line of two colors disappears. This causes a problem that the color output result and monochromatic output result look completely different from each other.
An object of the present invention is to solve the aforementioned problems.
The present invention has been developed in consideration of the above-mentioned prior art, and an object thereof is to provide an image processing device and method and a storage medium, in which when figures having different colors and the same density are adjacent to one another, a user can recognize these figures.
To attain this and other objects, according to a preferred aspect of the present invention, there is provided an image processing device, comprising: processing means for obtaining color data and gray-scale converted value of a processing object and color data and gray-scale converted value of another processing object adjacent to said processing object; first determining means for determining whether the gray-scale converted value of said processing object is similar to the gray-scale converted value of the processing object adjacent to said processing object; second determining means for determining whether the color data of said processing object is different from the color data of the processing object adjacent to said processing object; and control means for, when said first, second determining means determines that the color data are different and gray scales are similar to each other, control is performed to generate a difference in the gray-scale converted values of said processing object and the processing object adjacent to said processing object.
Another object of the present invention is to provide an inventive function.
Details and other characteristics of the present invention will be apparent from the following embodiments and drawings.